1. Fundamentals of Game Design, 2nd Edition
by Ernest Adams
Chapter 11: Game Balancing

2. Objectives List qualities that characterize a balanced game
Define a dominant strategy and discuss ways to avoid dominant strategies in player-versus-player and player-versus-environment games
Know how to use the element of chance in a game so that player skill still ultimately determines the outcome of the game
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Chapter 11 Game Balancing

3. Objectives (Cont.)
List strategies for making symmetric and asymmetric player-versus-player games fair
List strategies for making player-versus-environment games fair
Understand types of difficulty and explain ways to manage difficulty to maximize the player’s enjoyment of the game
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Chapter 11 Game Balancing

4. Objectives (Cont.)
Discuss the phenomenon of positive feedback and discuss ways to control positive feedback in the game
Recognize qualities of unbalanced games such as stagnation and triviality and explain how they can be avoided
List design methods that can make fine-tuning easier
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Chapter 11 Game Balancing

5. What Is a Balanced Game? A balanced game
Is fair to the player(s)
Is neither too easy nor too hard
Makes the skill of the player the most important factor in determining his success
Concept of balance differs between PvP and PvE games
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Chapter 11 Game Balancing

6. What Is a Balanced Game? (Cont.)
A well-balanced PvP or PvE game has the following characteristics:
It provides meaningful choices
It avoids dominant strategies
(They will be explained later)
Each strategy must have a reasonable chance of producing victory
Player’s skill must affect success
Role of chance should not be so great that player skill becomes irrelevant
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Chapter 11 Game Balancing

7. What Is a Balanced Game? (Cont.)
Additional balance requirements for PvP
Players perceive the game to be fair
A player who falls behind should have opportunities to catch up
Game rarely ends in a stalemate
Additional balance requirements for PvE
The player perceives the game to be fair
Definition of fairness is different—discussed later
Level of difficulty must be consistent, without spikes or sharp drops
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Chapter 11 Game Balancing

8. Avoiding Dominant Strategies
Dominant strategy is a strategy that reliably produces the best outcome a player may achieve, no matter what his opponent does
Dominant strategies are undesirable because a player has no reason to use any other strategy once she has discovered the dominant strategy
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Chapter 11 Game Balancing

9. Avoiding Dominant Strategies (Cont.)
Dominant strategies in video games
Transitive relationships among three or more entities
If A > B and B > C, then A > C
Never any reason to choose B or C if A is best
To correct the imbalance, assign costs to each choice
To create a more interesting choice, impose shadow costs for choices
Shadow costs are costs that are not immediately apparent
Transitive relationships often used to create upgrades for a player’s abilities—start with C, then earn B, then A
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Chapter 11 Game Balancing

10. Avoiding Dominant Strategies (Cont.)
Dominant strategies in video games (cont.)
Intransitive relationships (rock-paper-scissors)
If A beats B and B beats C, you can’t assume A beats C
Rather, A beats B, B beats C, and C beats A
RPS model is simple but can be adjusted by modifying core mechanics
Orthogonal unit differentiation—each kind of unit should be unlike the others in some way
Not simply more or less powerful, but uniquely different
Guarantees each kind of unit has a unique function
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Chapter 11 Game Balancing

11. Avoiding Dominant Strategies (Cont.)
Dominant strategies in PvE games
Implementing fewer actions in a game risks creating exploits—actions that can beat any challenge
Test thoroughly to eliminate exploits
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Chapter 11 Game Balancing

12. The Role of Chance
If chance plays a role, how to ensure the more skillful player wins?
Use chance sparingly
Use chance in frequent challenges with small risks and rewards
Allow player to choose actions
Allow player to choose how much to risk
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Chapter 11 Game Balancing

13. Making PvP Games Fair
To balance symmetric games, treat every player the same
Same rules, resources, victory conditions
Asymmetric games are harder to balance
One approach: give players identical quantities of materials or points when they start
Players spend points to build units as they wish
Players spend ponts to adjust unit attributes
Study Starcraft as a great asymmetric game
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Chapter 11 Game Balancing

14. Making PvP Games Fair (Cont.)
Balance issues for persistent worlds
Persistent worlds are never symmetric and always intrinsically unbalanced
New players need protection
Can be rebalanced on the fly by patching
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Chapter 11 Game Balancing

15. Making PvE Games Fair A fair PvE game should
Offer challenges at a consistent level of difficulty
Avoid learn-by-dying designs
Avoid stalemates
Provide information for critical decisions
Avoid requiring extrinsic information
Include challenges appropriate for the genre
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing

16. Managing Difficulty
Balancing a game includes managing the difficulty of its challenges to keep players within a flow state
Factors outside the designer’s control
Previous experience facing challenges similar to those in your game
Native talent such as hand-eye coordination and reasoning skills
A game that requires cheats to be winnable is badly balanced
Flow occurs when the player’s abilities balance the challenge.
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing

17. Managing Difficulty (Cont.)
Types of difficulty
Absolute difficulty—compare amounts of skill required and stress to that of a similar trivial challenge
Relative difficulty – difficulty relative to player’s power provided by the game
Power provided measures player’s strength by means appropriate to situation (e.g., weapon strength in shooters)
Perceived difficulty = absolute difficulty  (power provided + in-game experience)
Reminder from Chapter 9: Intrinsic skill needed to overcome challenge + stress = absolute difficulty.
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing

18. Managing Difficulty (Cont.)
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Chapter 11 Game Balancing

19. Managing Difficulty (Cont.)
Creating a difficulty progression
Perceived difficulty of challenges should stay the same or rise
In games for casual players and young children, it should remain almost flat
Relative difficulty must increase over time to counteract the player’s growing in-game experience
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Chapter 11 Game Balancing

20. Managing Difficulty (Cont.)
Establishing difficulty modes
In single-player games, allow player to choose a difficulty mode
When a difficulty mode is selected, challenges must stay within that range
If you can’t adjust the difficulty of a challenge, provide a way around it for the easy mode and block the go-around route for the hard mode
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing

21. Understanding Positive Feedback
Positive feedback occurs when a player’s achievement changes the game state, making future achievements easier
Benefits of positive feedback
Discourages a stalemate
Rewards success
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing

22. Understanding Positive Feedback (Cont.)
Controlling positive feedback
Don’t give too much power as a reward
Introduce negative feedback
Achievements have a cost as well as a benefit
Raise the absolute difficulty level of challenges as the player proceeds
Allow collusion against the leader in PvP games
Define victory as unrelated to the feedback cycle
Use chance to reduce the size of the rewards
Review the graphs in Figure 11.8.
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Chapter 11 Game Balancing

23. Other Balance Considerations
Avoid stagnation
Stagnation occurs when the player does not know what to do next
Hide clues in plain sight about how to proceed
Have the game detect when the player is wandering aimlessly and provide nudges in the right direction
Avoid trivialities
Let the computer handle uninteresting details of game
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing

24. Design to Make Tuning Easy
Generalize mechanics when possible
Try to avoid creating special cases
Separate code and data
Suggestions for efficient fine-tuning:
Modify only one parameter at a time
When modifying parameters, make big adjustments—the consequences are easier to see
Keep records
Use pseudo-random numbers
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing

25. Summary You should now understand How to design a fair game
How to avoid dominant strategies
How to use chance
How to manage difficulty
How to control positive feedback
© 2009 by Pearson Education, Inc.
Chapter 11 Game Balancing